Access Control Terminology
A
Access Area: A specific defined area wherein all access points to the area are secured by the system, and
the access points can be configured and adjusted to set parameters on occupancy and permission attributes.
Access Card: A coded employee card, usually the size of a credit card, recognizable to the access control
system and read by a reader to allow access. It can be used for photo identification of the cardholder and for
other data collection purposes. Card technologies include magnetic strips, wiegand-effect, proximity
(active/passive), barium ferrite, and smart/intelligent cards.
Access Code: Numeric or alphanumeric data which, when entered correctly, authorizes entry into a secure
area.
Access Control: Any system or method which automatically controls the passage of people and vehicles into
or out of an area or structure.
Access Control Card: An identification card with encoded information that, when presented to a card reader,
identifies the cardholder to an access control system, allowing that system to determine the cardholder's
entrance and exit rights.
ACM (Access Control Model): A group of objects that when associated together form a point of entry that is
normally associated with a door or elevator.
Access Control System: An interconnected set of controllers, managing the entrance and exit of people
through secure areas.
Access Credential: A medium that contains encoded information (which is recognized by the access control
system) such as ID cards, key fobs, biometrics, and smart chips.
Access Group: A superset of information including Time zones and secured Doors that is applied to
cardholders. This information defines at what time-of-day and through which doors cardholders are granted
access.
Access Level: The door or combination of doors and/or barriers an Individual is authorized to pass through.
Access Mask: Electronic alarm masking suppresses the annunciation of an alarm condition that would have
been reported in the “secure” mode of operation. Masking does not block the reporting ability of tamper or
fault conditions that may not be seen when alarm shunting is used.
Access Mode: The condition in which all access parameters have been met, allowing an access control
system to grant access.
Access Point: Each means of entry into a controlled security area, consisting of a card reader, monitor
switches and/or latches. Access points are wired to an access control panel.
Access Parameters: Programmed information that defines the conditions that must be met to grant access.
Such parameters may include access codes, access groups, authorization levels, or Time zones.
Access Request: The act of presenting the information necessary to verify a person's identity.
Access Time: The period of time during which an access point is unlocked. (Also see shunt time).
Acquired Data: The data collected from an event that is used to make a decision, or is saved for future
analysis.
Active Card: A type of access control card that is dependent upon a card reader to provide the power
necessary to allow the card to transmit its data.
Actuator: A manually operated or automatically controlled switch or sensor which initiates a signal that can be
processed by an access control system.
ADA (American Disabilities Act): Indicates that a setting or card designation is compliant with the American
Disabilities Act, which provides specific parameters for access for personnel with disabilities. Cards with the
ADA setting checked, enable ADA parameters to take effect when the card is badged.
Administrator: Person responsible for adding operators and assigning the specific privileges to the operators’
profiles, and determining operator levels.
Alarm Annunciation: The act of announcing that an alarm event has occurred. Annunciation can be done by
an audible alarm, warning lamp or LED, or a pop-up window or message (in the case of alarm monitoring via
computer software).
Alarm Disable: The ability to physically or electronically make an alarm input unaccessible to an access
control system.
Alarm Enable: The ability to physically or electronically make an alarm input accessible to an access control
system.
Alarm input: A device that is monitored by the access control panel. An alarm signal will be generated if the
device is activated.
Alternating current (AC): An electric current that reverses its direction regularly and continually. The voltage
alternates its polarity and direction at current flow negative to positive. AC current.
Access Relay: An electrically operated switch that is activated when access is granted to unlock a door.
Ampere (amp): The unit of measurement for the rate of electrical current flow characterized by the symbols l
(in Ohm’s law formulas) or A. One ampere is the current flowing through one ohm of resistance at one volt
potential.
Annunciator: An audible and/or visual signaling device.
Anti-Passback (APB; Anti-Tailgating): A feature that will not allow any card to re-enter unless it has been
used to exit. This requires that readers be used for both entry and exit.
Audit Trail: A means of recording and saving access control event history for later review.
Authorization Server: The Authorization Server maintains all client license and sub-controller license info.
Also manages concurrent clients.
Authorized Release Device: A device that when activated allows authorized persons to enter or exit
monitored and controlled openings without triggerring an alarm. The authorized released may be a keyed
switch, a card reader, a digital code reader and so forth
B
Badge: An identification card usually displaying a cardholder’s photo, signature or other specific identifying
characteristics.
Badge Reader: A reader used to read and interpret data encoded in an identification badge. See Card
Reader.
Badging Software: Security software that is capable of creating Photo Identification badges.
Badging Station: A hardware and software system used to obtain and save personal data about a cardholder
(e.g., photo or signature).
Bar Code: A method of encoding information using machine readable rectangular bars and spaces of varying
size and thickness to represent alphanumeric characters.
Bar Code Card: An access control card with identification information encoded in Bar Code format.
Bar Code Reader: A reader capable of reading and interpreting cards using bar codes to encode data.
Barium Ferrite Card: An access control card with identification information encoded in the card via magnetic
material embedded in the card.
Barium Ferrite Reader: A reader capable of reading and interpreting cards using barium ferrite to encode
data.
Batch Programming: A method for processing data or performing tasks in which a number of commands are
collected and then processed by a controller all at one time.
Battery Backup: A secondary energy source used to power devices in the event the primary energy source
fails. Battery Backup typically provides power for a short period of time, allowing for immediate action, system
protection, and system shutdown before the battery reaches a drained state.
Battery standby: A means of automatically switching over to stored battery power during local primary power
failure.
Baud: The unit of data signal transmission speed, typically expressed in bits per second.
Bell Transformer: A small transformer used to reduce power line voltage to the level required by low power
devices (i.e. card readers)
Binary Coded Decimal (BCD): The decimal numbers 0 through 9 expressed in a 4-bit binary format.
Biometrics: A machine readable technology that allows for the identification of individuals by reading unique
biological features (i.e. fingerprints, hand geometry, voice analysis, the retinal pattern in the eye).
Biometric Access Control: Access control where the identification process is made through biometric
parameters. See Access Control, Biometrics.
Bit: An abbreviation for "binary digit" in the binary number system. A bit will have the value of either 0 or 1.
Break: To open an electrical circuit.
Break Before Make: A type of switch in which one set of contacts open before another set of contacts closes.
Brownout: Low line voltage that can cause misoperation of and possible damage to equipment. For example
a motor that tries to start at low voltage can actually be in a lock-rotor condition and can overheat.
Bus: 1) In power systems, a solid metal or uninsulated wire connector from which a universal type of power or
ground connection is made. 2) In computer or data transmission systems, the principal channel through which
all major sections communicate.
Buffer Capacity: Refers to the amount of information the system can store, this may include the users, time of
day and specific door.
Bumping: Sending an alarm to an alternate site or station following a user-defined time during which the
alarm is unacknowledged.
Byte: A group of eight binary data bits.
C
Cam: A rotating eccentric piece attached to the end of a cylinder plug to actuate a lock or latch mechanism.
Card: An identification device assigned to an individual that identifies that individual. Typically, it is the size of
a credit card. See Access Card, Key Tag.
Card Access: A type of access control system using encoded cards and card readers to identify cardholders
and determine if access may be granted. See Cardholder.
Card Encoder: A device used to encode data onto an access card.
Card Reader: A device that retrieves information stored on an access card and transmits that information to a
controller.
Cardholder: An individual who has been assigned an access control card or tag.
Central or on line processing- A system where all systems information is stored in a central location and all go
or no-go decisions are made by this unit.
Central or on line processing: A system where all systems information is stored in a central location and all
go or no-go decisions are made by this unit.
Channel: The path in which the SSP controller communicates with the host or driver.
Checksum: An additional set of information transferred with a computer program or a data stream that is used
to verify the accuracy of the data just transferred.
Chip-In-Card: See Smart Card.
Circle of Protection: A security plan in which the items to be protected are surrounded by two or more
protective zones of increasing size. For example, a bank vault may have the heavy vault door, followed by a
controlled access door into the vault area, followed by the bank building with an alarm system.
Circuit: The path through which electrical energy flows.
Circuit Breaker: A switch on an incoming power circuit that opens if abnormal circuit conditions arise (such as
an overload or short circuit).
Circuit, closed: (1) An electrical circuit in which current normally flows until interrupted by opening of a switchtype electronic component. (2) A circuit or switch in which the contacts are open during normal operations.
Circuit, open: (1) An electrical circuit in which current does not flow until permitted by the opening of a switch
or a switch-type electronic component. (2) A circuit or switch in which the contacts are closed during normal
operations.
Closure: The point at which two contacts meet to complete a circuit.
Coercivity: The property of a magnetic material, as on magnetic stripe keys, which is a measure of the
coercive force. It is used when describing the strength of magnetic saturation when discussing magnetic stripe
card keys.
Coil, electric: Successive turns if insulated wire that created a magnetic field when an electric current is
passed through them.
Command: An operator-initiated event that causes a change or action within the access control system.
COM Port: A hardware device that allows a computer to communicate with external devices.
Conductor: A material that readily allows electricity to flow through it. Most metals are good conductors.
Conduit: A tube or trough for protecting wires and cables. It may be a solid or flexible tube in which insulated
electrical wires are run.
Connector: Generally, any device used to provide rapid connect/disconnect service for electrical cable and
wire terminations.
Contact: A magnetically or electrically controlled connection point that opens or closes to interrupt or allow the
flow of current.
Contact Rating: The load rating of a switch, listed by maximum voltage and/or current accepted by the switch.
Continuous duty: Refers to a device or a control that can operate continuously with no off or rest periods.
Control Center: A central location in a secure area where access and alarm sub-systems are supervised and
security personnel are located.
Control Point: An exit or entry point such as a door, turnstile, or gate, where access is controlled.
Controller: A microprocessor based circuit board that manages access to a secure area. The controller
receives information that it uses to determine through which doors and at what times cardholders are granted
access to secure areas. Based on that information, the controller can lock/unlock doors, sound alarms, and
communicate status to a host computer. Includes the SSP, SSP-C, and SSPE.
CSA: The CSA label on a product signifies that the product has met requirements set by CSA International,
and that the product manufacturer is authorized to use the CSA symbol on their products.
Current: The flow of electrons through an electrical conductor. Current is measured in amperes.
Cypher Lock: A digital push-button combination lock.
D
Database: A collection of data used and produced by a computer program. The files created at the host of the
access control system forms its database.
Deadbolt: A bolt operated manually and not actuated by springs. When locked, the bolt can not be forced
back. A deadbolt is operated (projected and retracted) by a key cylinder or lever handle.
Deadlatch: A latch in which the latchbolt is positively held in the projected position by an auxiliary
mechanism.
Decibel (dB): An increment of measurement used to compare measured levels of sound energy (intensity) to
the apparent level detected by the human ear, expressed as a logarithmic ratio.
Dedicated I/O Point: An input or output that is dedicated to a specific function. Often, dedicated input points
can be assigned to initiate tasks such as an Auxiliary RTE, and a dedicated output point can be assigned to
initiate tasks such as the annunciation of Door Forced or Door Held Open alarms.
Dedicated Telephone Line: A telephone line directly connecting two points. Also Known As - Lease Line.
Deenergize: To remove power.
Degausser: A device that creates a strong magnetic field that erases data from magnetically encoded media
such as magnetic stripe cards.
Degraded Mode: A mode of controller operation that provides a minimal authorization level in the event of
controller failure.
Delay: A period of time before or during an event.
Delay on break: A term used to describe a mode of operation relative to timing devices. The delay begins
when the initiate switch is opened (delay break of initiate switch).
Delay on energization: A term used to describe operation relative to timing devices. The delay begins when
the initiate switch is closed or application of power to the input.
Device Address: Value set on an access control device to determine its unique identity.
Direct current (DC): Electrical current that travels only in one direction and has negative and positive polarity.
It may or may not have an AC ripple component. DC sources that are unfiltered should be referred to as fullwave or half-wave rectified circuits.
Distributed Access Control: Access control systems in which all control decisions are made at the local
controllers, independent from a host computer. Local Controller events are uploaded to a host computer
periodically for review and storage.
Distributed Intelligent Devices: Access control devices that make their own access decisions uploading
event messages periodically to the central processing unit for storage.
Distributed processing: An access control system where some of the system information is stored at the
individual readers or controllers. This allows the system to operate when the host is down or not
communicating.
Door: A generic term for a securable entry way. In many access control applications a "door" may actually be
a gate, turnstile, elevator door, or similar device.
Door Forced Alarm: An alarm generated when a door is forced open, opening the door switch contact. This
requires a status switch and some type of rex device.
Door Held Open Alarm: An alarm generated when a door is held open beyond the designated period of time
(as programmed by access control software). This is used to prevent someone from using a card to enter and
then leave the door open for others. This requires a status switch on the door.
Door Held Open Time: The amount of time from when a door is opened before an alarm is generated for the
door being opened too long. This is often used to monitor if a door is being propped open following a valid
access request.
Door status switch: A DSS is a switch used to monitor whether a door is in an opened or closed position.
Door Switch: A switch that reflects the state of the door: if the door is open, the switch is open -- if the door is
closed, the switch is closed.
Double pole, double throw, (DPDT): A term used to describe a switch or relay output contact form (2form C)
in which two separate switches operating simultaneously, each with a separate normal closed contract and a
common connection. This form is used to make and break two separate circuits.
Download: Sending information from a host computer to a peripheral device in an access control system. An
“update” action to send saved information to the SSP. See Save.
Dry contract: Metallic points making (closing) or breaking (opening) a circuit. The switch circuit must have its
own source of power and is merely routed through the dry contacts.
Duress: Forcing a person to provide access to a secure area against that person's wishes.
Duress Alarm: A device that generates a silent alarm signal in the event a person is experiencing Duress.
This device may be a standalone signaling device or it may be incorporated into a reader.
Duress Code:An alphanumeric code which, when entered into an access control system, alerts the system to
a Duress condition.
Duty Cycle: The ration of system ON time to system OFF time.
E
Egress: Passage through an opening in the exit direction, especially passage that leads out of a structure
(opposite of ingress).
Easy egress: A means of exiting where the person wishing to leave simply turns the doorknob to exit.
Earth Ground: An electrical connection point that brings all electrically neutral lines to the earth's surface
potential (essentially zero potential). A good earth ground helps to protect electrical devices from damage
caused by transients such as power surges and lightening strikes, and drains electrical interference from data,
communication, and power lines that support these electrical devices. See Ground.
Electric Door Lock: A remotely operated electric locking device. See Electric Strike, Electromagnetic Lock.
Electric Strike: A door unlocking device that is installed in the door jamb and that works in conjunction with a
mechanical lock or latch mechanism. Requires power to be applied to unlock a door.
Electric Door Strike: An electric door locking device, usually solenoid operated, that will unlock a door when
electric power is either applied, or removed, depending upon the configuration.
Electrified Lock: A mechanical locking device that has been modified to allow an electric circuit to lock or
unlock it.
Electromagnetic: A general term referring to the electric and magnetic fields associated with the movement of
electrons through conductors.
Electromagnetic Interference (EMI): Excess electromagnetic energy radiated by an electrical device that
may affect the operation of other electrical devices.
Electromagnetic Lock: An electric door lock that uses an electromagnet to hold a door closed. See Magnetic
Lock.
Embossed Card: An access control card that uses a raised pattern as a means of encoding data.
EMI: See Electromagnetic Interference
Enclosure: A box or cabinet usually constructed of metal, which houses system components, such as circuit
boards and other electronic and electrochemical controls and circuitry.
Encoding: The process of writing data to a card.
Energize: To apply power.
Entrance Delay: See Door Held Open Time.
EPROM: An acronym for Erasable Programmable Read Only Memory. A programmed memory (often in a
chip) that can not only be read, but can be repeatedly erased under high-intensity ultraviolet light and
reprogrammed.
Event: An occurrence at a controller (such as unlocking a door, requesting to exit, forcing a door open) that
generates a message stored by the controller.
Exit Alarm: A device that indicates (either audibly or silently) that a secure door has been forced opened.
Executive Privilege: An option which allows a cardholder unlimited access to all operational access points.
Access may be without the system referring to any other access parameters, or there may be a PIN-code
requirement that has been enabled.
Exit Lock: A push-bar door lock that spans the width of the door, used for emergency exit. An Exit Lock may
be connected to an Exit Alarm.
Exit Reader: A reader used to control exiting from a secure area.
Exit Switch: A switch that is used to initiate a Request to Exit. A push button, switch mat, proximity detector,
or other device which starts a timer in the reader interface electronics when someone is leaving through a
controlled entry or exit. The timer bypass (shunts) the door-open detector for a selected period of time.
F
Facility Code: In card access, a portion of the identifying characteristic of an access credential that is
common to a group of users in secured facility.
Fail-Secure: An electric lock that requires power to unlock. Also called fail-locked.
Fail-Secure Door: A fail-secure door is one that if the power should fail at that door, the door will automatically
lock and not allow entrance, but will continue to allow exit. A fail-secure door ensures a secure area remains
secure regardless of the situation.
Fail-Safe Door: A fail-safe door is one that if the power should fail at that door, the door will automatically
unlock allowing exit and entrance. A fail-safe door ensures people will be able to exit a secure area through
that door in the case of an emergency.
Fail-Unlocked: An electric lock that automatically unlocks with any power interruption. Also called fail-safe.
False Alarm: An alarm signal generated without an existing alarm condition.
Fingerprint Pattern Area: The identifying characteristics of a fingerprint, consisting of the arches, loops, and
whorls in the fingerprint.
Fingerprint Reader: A biometric reader that identifies a person based on the person's fingerprint pattern.
Fire door: A door that has been certified as a fire and smoke barrier. Special rules govern fire doors, including
permissible hardware that can be installed.
Fire door latch: A latch that has a 3/4 inch throw and an antifriction retractor.
Form C contact: A relay or switch mechanism that contains three terminals (normally open, common, and
normally closed).
Fuse: A protective device, placed in a circuit as a safeguard, that contains a metal. When the current flow
becomes too great, the metal melts, thus breaking the circuit.
G
Gate: Typically, a door that is outdoors.
General Protection Fault: An operating system fault that occurs whenever a program executes a command
that the operating system considers dangerous to the operating system. When a GPF is generated, the
program that generated the GPF is closed and control is returned to the operating system.
Glass break station: A device mounted near the exit door that can be used to release the door in the event of
an emergency.
Global Unlock: A normally-open input that, when closed, generates a signal that unlocks all doors in the
access control system.
Global Linking: An input at one Access Control panel affecting the output at another.
Ground: 1) An electrical connection with a ground potential point. 2) An electrical connection to a circuit's zero
voltage reference point. See Earth Ground.
Group: A logical set of common data objects such as cardholders or hardware points.
Guard Tour: A defined route of a security guard.
H
History: A log of system activity that can be recalled by utilizing the report command. Most systems offer a
feature that notifies the console operator of the amount of available storage for history information preventing
information from being written over. The message will usually alert the operator to archive the information onto
a removable magnetic tape.
Historical Log: A chronological record of events.
Hand Geometry: A biometric access control technology that verifies a person's identity by using the variations
in hand size, finger length, and finger thickness.
Host: Generally, it is the machine on which the driver resides. Sometimes refers to a given client machine,
e.g. in reference to a host-based macro.
Host Computer: The central controlling computer from which access control software applications are run.
Host Settings: The settings which determine the behavior of the application at the host or workstation.
HSPD-12: In an effort to reduce identity fraud, enhance security, increase government efficiency and protect
personal privacy, Homeland Security Presidential Directive 12 was issued Aug. 27, 2004, to establish a
mandatory, government-wide standard for secure and reliable forms of identification issued by the federal
government to its employees and contractors.
I
Identification: The act of recognizing one person as being unique from all other people.
Identification Card: A card that stores the information necessary to verify the identity of the cardholder.
Info-Ready Reporting: A software development architecture that presents relevent system data directly within
the application rather than having to run multiple external reports. NPower DNA allows operators to filter
system events through simple drag and drop function as well as making common reports, such as "who has
access", available from the right click context menu.
Infrared Light: Light with a wavelength that is too low to be seen by the human eye.
Infrared Motion Sensor: A sensing unit that detects motion based on the disruption of infrared light waves.
Ingress: Enter (opposite of egress).
Input: An electronic sensor on a controller that detects a change of state in a device outside the controller.
See Normally-Closed, Normally-Open
Input voltage: The designed source requirement needed by equipment in order to operate properly.
Inrush: The initial surge of current through a load when power is first applied. Lamp loads, inductive motors,
solenoids, and capacitive loads all have inrush or surge current. Resistive loads, such as heater elements,
have no inrush.
Insertion Card: A card that must be inserted into a reader for the reader to retrieve the information stored on
the card.
Intelligent Device: Any type of microprocessor-based input, output, or sensor device that has free-standing
logic capability. These devices can be programmed with instructions that allow them to make their own
decisions regarding granting access and sounding alarms. They also can communicate with a host computer
to receive new instructions or to send event message logs.
Interlock: A system of multiple doors with controlled interaction. Interlocks are also known as light- traps, airtraps, man-traps, and sally-ports (see security interlock).
Intermittent duty solenoid: A solenoid designed to be energized for short periods of time. Continuous
operation may damage an intermittent duty solenoid.
ISO 14443: An international standard for contactless smart cards operating at 13.56 MHz, 14443 sets
communication standards and transmission protocols between cards and card readers to create
interoperability for contactless smart card products.
K
Key Tag: An access control identification device assigned to an individual to give that individual access rights
to an access control system. Typically, the tag is attached to a key ring or similar device to provide quick,
convenient access to the tag. Each tag has a unique identification code. That identification code is used by a
controller to determine through which doors and at what times of day cardholders are granted access to a
secure area. See Card
Keyless Access Control: An access control system that controls access using something other than a key
and a lock; typically some kind of reader and an electric door lock.
Key Switch: A lockable switch operated by a key.
Keypad: An alphanumeric grid which allows a user to enter an identification code. A flat device which has
buttons that may be pressed in a sequence to send data to a controller, and which differs (said to be “nonQUERTY”) from a typewriter-like computer board.
L
Landscape: Horizontal orientation of pages, screen displays or badges.
Latch: The locking of a circuit by means of a holding contact; used in relay logic when a momentary initiation
is required.
Latching Relay: A relay that when set (either ON or OFF depending upon the relay configuration), locks into
place until reset either manually or by a signal.
LCD: The abbreviation for Liquid Crystal Display.
LED: The abbreviation for Light Emitting Diode. A diode, a solid-state device, that gives off virtually heatless
colored light when electric current is passed through it. LED’s are very efficient and long lasting and are often
used for digital readouts and annunicators. Common colors include red, green, and amber.
Lease Line: See Dedicated Telephone Line.
Line Drop: The drop in voltage along a power line caused by the resistance, reactance, and/or leakage in the
line's wires.
Line voltage: The voltage existing in a main cable or circuit, such as a wall outlet.
Listed: Refers to equipment or material included in a list states that the equipment or material met appropriate
standard or has been treated for and suited to a specific application.
Load: Any device that converts the computer system’s digital information into analog information and
transmits it over a telephone line. Another modem must be used when the information is converted back from
analog to digital.
Load rating: A control specification outlining the type of load the minimum (min) the maximum (max) currents
ands the voltage.
Local alarm: A visual or audible signaling device located at a monitored door, window or other opening.
Lock Relay Output: A relay on the controller that changes its state upon command by the controller, locking
or unlocking a secure door.
Lock status sensor (LSS): Relay type to operate the LED with an SPDT switch to indicate low voltage and
tampering of the lock face locally or to a remote monitoring location.
Logging: Creating and storing a permanent record of events that can be reviewed, printed, and analyzed.
M
Machine Readable: A code or characters that can be read by machines.
Macro: A defined set of actions or commands that can be manually executed by the operator or is based on a
trigger event.
Magnetic Contact: A device that sends a signal when the magnetic field between two monitored points is
broken.
Magnetic Lock: A door lock made up of an electromagnet and a strike plate. The electromagnet is mounted in
the door frame; the strike plate in the door. When power is applied to the electromagnet, the strength of the
electromagnet keeps the door locked.
Magnetic Stripe: A band of ferrous material that is sealed onto or into a card key or credit card used to
encode cardholder information.
Magnetic Stripe Card: An access control card with a strip of recordable magnetic material, on which data is
encoded.
Magnetic Stripe Reader: A reader capable of reading and interpreting cards using magnetic stripes to encode
data.
Maintained contact switch: A switch designed for applications requiring sustained contacts but with provision
for resting.
Masking: Hiding or suppressing alarms that the operator does not wish to be viewed.
Master Code Card: An access control card that grants access and exit at every card reader on the system.
Memory: The section of a host computer or a controller in which data and instructions are stored.
MODEM- A MODulator dEMulator. An electronic device that allows communication between electronic devices
by converting computer serial data to an analog format that can be transmitted and received via telephone..
Mode of operation: The specified operation condition of a switch, lock, door system, and so forth.
Momentary duty lock: An electric lock equipped with a solenoid that is energized only momentarily.
Momentary Switch: A spring loaded contact that when pressed, closes two contacts. When pressure is
removed the contacts open.
Motherboard: A master printed circuit board used to interface the activities of individual printed circuit boards
and the devices being controlled monitored. The motherboard is usually located on the back of a control panel
assembly; individual printed circuit boards plug into it.
MOV: Metal oxide varistor, a device used to prevent the emf generated by the locks from damaging the
control.
MPG (Monitor Point Group): A collection of monitor points that typically have been grouped for common
manageability.
N
National Electrical Code (NEC): A consensus standard published by the National Fire Protection Association
(NFPA); commonly called "code".
Network: 1) A series of controllers, all connected via a communications cable. 2) A group of computers, all
connected via a communications cable.
Noise: The unwanted and/or unintelligible signals picked up on a cable circuit.
Normally-Closed:The state of an input device that continually keeps a circuit closed or complete until forced
by an action or event to open that circuit. See Input.
Normally-Open: The state of an input device that continually keeps a circuit open or incomplete until forced
by an action or event to close that circuit. See Input.
O
Ohm: The unit of measurement of resistance.
Online Help: A reference program within most software programs that provides basic descriptions and
instructions on how to use that software program.
Operating voltage: The voltage by which a system operates; a nominal voltage with a specified tolerance
applied; the design voltage range necessary to remain within the operating tolerance. For example, for a
system specified 120 volts +/- 10 percent of normal, 120 volts is the nominal voltage and the design voltage
range is 108 to 132 volts AC.
Operator: Anyone with access to the application. The Administrator is also an Operator, though generally
distinguished in the documentation due to the difference in responsibility and permissions.
OR Gate: A logic circuit that requires that any input must be in a high state (logic 1) to generate a high state
output (logic 1).
Output Relay: A device that changes its state upon receiving a signal from a controller. Typically the state
change prompts an action outside of the controller such as activating or inactivating a device. The auxiliary
relays found in access control panels or NODES that control external devices.
Output voltage: The designed power source produced by a power supply to operate equipment.
P
Panel: Synonymous with an SSP. See Controller.
Panic Bar: A device, usually a small electrical switch in a mounting plate, used for unlocking a door in an
emergency. A quick release door lock allowing the door to be quickly opened in the case of an emergency
situation. Also Known As - Crash Bar.
Parking Gate: A barrier that can be opened or closed to control vehicular access
Passive Infrared (PIR) Detector: A motion sensing device, often used for intrusion detection systems, can
also be used to unlock a door as someone wishing to egress approaches.
Password: The permission level of the operator environment. Required for permission to log on to the
application.
Photo Badging: See Badging Software.
Personal Identification Number (PIN): A unique numerical code used to identify an individual.
Personal Identity Verification (PIV): requirements for federal employees and contractors. The Department of
Commerce and National Institute of Standards and Technology (NIST) were tasked with producing a standard
for secure and reliable forms of identification. In response, NIST published Federal Information Processing
Standard Publication 201. The program includes the technical requirements for improving the identification and
authentication of federal employees and contractors.
Piggybacking: 1) More than one individual entering a secure area using one access card. 2) Following an
authorized person into a secure area. Also Known As - Tailgating. See Anti Passback.
PIN: A Personal Identification Number assigned to a user. It is used either by itself or in conjunction with a
card.
Portrait: Vertical orientation of pages, screen display or badges.
Potentiometer (pot): Variable resistor, manually adjustable.
Pre-Alarm Held: An alert given before an opened door reports “held open” alarm.
Primary: The transformer winding that received energy from a supply circuit.
Primary Code: The main identification information provided by an individual to gain access to a secure area.
See Auxiliary Code.
Printed circuit board: A means of making electrical interconnections without using insulated wires. Printed
circuit boards provide a supporting and insulating medium for component and conductors in a form that is
readily adaptable to mat assembly.
Programmable Card: A card in which data may be encoded.
Programmable Card Reader: A card reader in which instructions for granting or denying access may be
programmed.
Proximity: A non-contact system for reading cards. Data is exchanged between card and reader by radio
frequency, fiber optics, induction, laser or other non-mechanical contact technology.
Proximity Card: A card using proximity technology to store and transmit encoded data.
Proximity Reader: A reader capable of reading and interpreting cards using radio frequency identification to
encode data.
Push-Button Lock: A locks that opens when a set of push-buttons are pressed in sequence or in unison.
Q
QPL: The Qualified Products List, published by TSA, includes biometric technology that can be used for
airport access control. Being on the QPL ensures the product has passed testing conducted by NIST.
R
Radio Frequency Identification: A method of reading a card using radio frequency energy to transmit
information from the card to a reader. See Proximity.
RAM: See Random Access Memory.
Random Access Memory (RAM): Randomly addressable, readable and writable memory (either volatile or
nonvolatile) whose contents may be read or be altered at will.
Rated voltage: The maximum voltage at which electric component can operate for extended periods without
undue degradation or safety hazard.
Reader: A device that can read the encoding on a card or badge. Refers to the “front end” that a user must
interact with to allow access. Readers can be keypads, card readers, proximity readers, etc.
Rectifier: A solid-state electrical device that will allow current to flow in one direction only. It is designed to
convert alternating current to direct current.
Recycle time: The time needed to reset and rein the timing function and remain within the specified timing
tolerance. Recycle time is generally specific "during timing" or a "after timing".
Regulated power supply: A power supply provides a constant output regardless of voltage variation.
Relay: A device that is capable of opening a normally-closed circuit or closing a normally-open circuit. When
the relay is not energized, the normally-closed circuit is complete and the normally-open circuit is open. When
the relay is energized, it switches roles, opening the normally-closed circuit and closing the normally-open
circuit. This dual nature of a relay allows for two types of applications: a device may be attached to the
normally-closed circuit so that the device is always on until the relay energizes to turn it off, or a device may be
attached to the normally-open circuit so that the device is always off until the relay energizes to turn it on.
Request to Exit (RTE): A signal that informs the controller that someone has requested to exit from a secure
area.
Remote alarm: A visual or audibly signaling device used to signal violations at locations removed from the
central control station or monitored open. For example, a remote alarm may be placed roof, in a stair tower, or
at guard station outside a building.
Remote Host: A system where the main computer that controls the system is remotely located. It allows a
single computer to control multiple systems.
Remote reset: A switch located at a monitored opening. If a violation occurs, the alarm at the control console
can not be turned off until the area is secured and the remote reset is activated. Its purpose is to ensure the
inspection of an opening that has been violated or left open.
REX Button: A Request to exit button. A device that must be pushed in order to release the door.
Read Only Memory (ROM): Nonvolatile memory whose contents are programmed into the ROM when the
ROM is made, and therefore cannot be altered. ROM is typically used to store programs and fixed data sets.
Real Time Command: A command that is executed immediately, with no time delay.
Remote Host: A system where the main computer that controls the system is remotely located. It allows a
single computer to control multiple systems.
Reset time: The time required to return the output to its original condition.
Resistance: The opposition to the flow of an electric current (measured in ohms); the reciprocal of
conductance.
Resistor: A circuit element whose chief purpose opposes the flow of current, causing a decrease in voltage.
RFID: Radio-Frequency Identification refers to small electronic devices that consist of a small chip and an
antenna. The antenna is capable of longer distances than proximity card technology and can be tracked
continuously regardless of whether the individual is next to a card reader.
ROM: See Read Only Memory.
RS-232: A serial communication protocol used for connecting data terminal devices. RS-232 is the most
commonly used communication protocol.
RS-485:A serial communication protocol used for multi-drop communication applications. It is used for higher
speed and longer distance communications.
RTE: See Request to Exit.
S
SSP (also SSP-C, and SSP-E): Synonymous with panel and controller. See Controller.
Save: An action to record information in the database. See Download.
Secondary: The transformer winding that receives energy by electromagnetic induction from primary.
Generally the output of the transformer to the low voltage device.
Secure Area: A designated area in which access into and out of is controlled and can be monitored.
Secure Door: A door in which access through is controlled and can be monitored.
Security condition sensor (scs): A sensitive crystal relay to operate the LED with an SPOT switch indicate
low voltage and tampering of the lock locally or to a remote monitoring location. Primarily used in high security
applications.
Schedule: Programming of an access control system that automatically locks and unlocks doors, or that
performs other functions based on day and time.
Security interlock: A multi-door system in which doors are normally closed and locked; releasing doors
disables the releases for release for all other doors until the first door is closed and relocked (see interlock).
Shielding: Providing electrical isolation for a circuit, component, or wire by enclosing or isolating the circuit,
component, or wire with a metal enclosure, plate, or foil that blocks any interfering electrical field.
Short Circuit: An unintentional connection that provides a low resistance path between two points in a circuit
or between a point in a circuit and ground. A Short Circuit can drastically affect the operation of a circuit. If
excessive current flow results from the Short Circuit, a device may be damaged or ruined.
Shunt: Electrical term for bypassing. In access control it is common to shunt an alarm sensor, such as a door
position switch, when a door is about to be opened for valid access or egress.
Shunt Time: The time in seconds that a door-open alarm is suppressed after the door has been opened.
When a door is released the status switch is automatically "shunted" for a period of time to allow the person to
enter/exit. If the time is exceeded a door held open signal will occur.
Signature Verification: A biometric identification method using a person's signature characteristics (writing
speed, pen pressure, shape of loops, etc.) to identify that person.
Single pole, double throw (SPDT): A term used to describe a switch or relay contact from (1form C), that has
a normally open and a normally closed contact with a common connection.
Single pole, single throw (SPST): A switch with one moving and one stationary contact, available either
normally open (NO) or normal closed.
Smart Card: A plastic card with an embedded microchip, which can be used to store information about the
cardholder or record card transactions as they occur.
Solenoid: An electro-mechanical device that operates the lockbolt. When electricity is applied, a mechanical
motion is obtained that moves the bolt.
Spike: A voltage peak of high amplitude and short duration. See Transients.
Springlatch: A plain latch switch, a beveled latchbolt that is activated by springs.
Standalone: In access control, this term usually refers to a device that identifies the user (keypad, reader,
etc.) and that makes an access decision. Some standalone units also contain a locking device and/or a power
source.
Strike: A plate mortised into or mounted on the door jamb to accept and restrain a bolt when the door is
closed. In some metal installations or with a deadlock, the strike may simply be an opening cut into the jamb.
(Synonym: keeper)
Strike Plate: A plate, usually made of metal, mortised into or mounted on the door jamb to accept and restrain
a bolt when the door is closed.
Status switch: A magnetic contact mounted on the controlled door. It is used to detect door held or door
forced.
Sub-controller: One of a series of circuit boards that communicates information about field devices like
readers, contacts, motion detectors, etc., upstream to the SSP. (RSC-1, RSC-2, RSC-T, ISC-16, and OSC-16)
Suppression: The addition of a device to an electrical circuit that minimizes or prevents transients from
affecting the proper operation of that circuit.
Switch: A device used to either connect or interrupt an electronic circuit.
T
Tamper: (1) A digital input that, if open, signals a cabinet tamper alarm at the device. (2) A digital input that
signals power loss alarm at the device.
Tailgating: 1) More than one individual entering a secure area using one access card. 2) Following an
authorized person into a secure area. Also Known As - Piggybacking. See Anti Passback.
Telephone Entry: An access control system that allows users outside a secure area to use a telephone to
contact someone inside the secure area and request access.
Time and Attendance: A system for recording worker arrival and departure times for the purpose of payroll or
other management functions.
Time Schedules: Consist of time ranges that are associated with days or holidays. Time Schedules are used
in connection with access levels and often as trigger events.
Time zones: A period of time that has been programmed into an access control system during which
authorized users either can or cannot gain access.
Touchpad: See Keypad.
Transients: Electrical surges or spikes conducted through power or data lines. Transients are typically
generated as electrical devices are turned on or off. See: Suppression.
Transaction: A record created that contains pertinent information about an occurrence in the access control
and monitoring system.
Transformer: An electric device that changes voltage in direct proportion to current and in inverse proportion
to the ratio of the number of turns of primary and secondary windings. The output low-voltage side is called the
transformer secondary.
Transient: Any increase or decrease in the excursion of voltage, current, power, heat and so forth, above or
below a nominal value that is not normal to the source.
Transient Suppressor: A device that protects data lines from high transient such as lighting and inductive
loads. They are recommended where there are data communications lines between the reader and its
electronics which are subject to high-transient situations. Two are required: one at each end of the exposed
communications lines.
Transorb: An electrical suppression device. See: Suppression.
Trigger: A system event that causes another event or macro to occur.
Turnstile: An entryway that uses a mechanical device to restrict entry to one person at a time.
TWIC: Transportation Worker Identification Credential. TWICs are tamper-resistant biometric credentials for
workers who require unescorted access to secure areas of ports, vessels, outer continental shelf facilities and
all credentialed merchant mariners. So far, TSA has to put TWIC on the back burner for aviation.
Twisted Pair: A cable that consists of one or more pairs of insulated wires that are twisted around one
another. Twisted pair is often specified for circuits carrying data.
U
Underwriters Laboratories Inc-UL: The UL label on a product signifies that the product has met the
Underwriters Laboratories requirements and that the product manufacturer is authorized to use the UL symbol
on their products. An independent, not-for-profit organization which tests products in the interests of public
safety.
Upload: Sending information from a peripheral device to the host computer in an access control system.
US-VISIT: Using digital finger scans and photographs, the federal government checks visitors to the U.S.
against a database of known criminals and suspected terrorists.
V
Verification: Identifying an individual based on some type of provided information. Verification may be done
using by methods such as access cards, biometric information, PIN, etc.
Voice Recognition System: An access control system that verifies a person's identity by comparing
previously stored voice recordings key words or phrases with the same key words or phrases spoken at the
time access is requested.
Volt (V): A unit of electromotive force, It is the difference of potential required to make a current of one ampere
through a resistance of one ohm.
Voltage: The term most often used (in place of electromotive force, potential, potential difference or voltage
drop) to designate electrical pressure that exists between two points and is capable of producing between the
two points.
Voltage drop: Voltage loss experience by electric circuit due to two principal factors: (1) wire size and (2)
length of wire runs.
Volt/amp (VA) rating: The product of rated input voltage multiplied by the rated current. This establishes
"apparent energy" available accomplish work.
W
Watt: The common unit of electrical power. A watt is dissipated by a resistance of one ohm through which
one-ampere flows.
Wiegand Card Key: A plastic card, approximately the shape of a credit card, which has an embedded module
of inert, specially treated ferromagnetic wires which generate a voltage pulse that can be sensed by a coil
within the card reader.
Wiegand Card: An access control card based on the Wiegand effect. Small bits of specially processed wire
are embedded in the card in a pattern that uniquely identifies the card. This identification information can then
be decoded by a Wiegand reader.
Wiegand Compatible Devices: A propriatary coding format for information used by many of the suppliers of
cards, key tags, proximity readers, magnetic stripe readers, bar code readers, and related items.
Wiegand Effect: Electrical pulses generated when individual sections of specially processed magnetic wire is
passed by a pickup coil. Each section of this magnetic wire has its own magnetic field. Depending upon the
strength of the individual magnetic fields, the pickup coil either senses a strong field or overpowers a weak
field, which generates an electrical pulse.
Wiegand Reader: A reader capable of reading the information encoded on a Wiegand card.
Z
Zone: A specific of protections; a portion of a large protected area.